<?php
class Image {
    private $file;
    private $image;
    private $info;
    
  public function __construct($file) {
    if (file_exists($file)) {
      $this->file = $file;
      $info = getimagesize($file);
      $this->info = array(
              'width'  => $info[0],
              'height' => $info[1],
              'bits'   => $info['bits'],
              'mime'   => $info['mime']
          );
          
          $this->image = $this->create($file);
      } else {
          exit('Error: Could not load image ' . $file . '!');
      }
  }
    
  private function create($image) {
      $mime = $this->info['mime'];
      
      if ($mime == 'image/gif') {
        return imagecreatefromgif($image);
      } elseif ($mime == 'image/png') {
        return imagecreatefrompng($image);
      } elseif ($mime == 'image/jpeg') {
        return imagecreatefromjpeg($image);
      }
    }  
  
    public function save($file, $quality = 90) {
      $info = pathinfo($file);
         
      $extension = strtolower($info['extension']);
         
      if (is_resource($this->image)) {
        if ($extension == 'jpeg' || $extension == 'jpg') {
          imagejpeg($this->image, $file, $quality);
        } elseif($extension == 'png') {
          imagepng($this->image, $file);
        } elseif($extension == 'gif') {
          imagegif($this->image, $file);
        }
           
        imagedestroy($this->image);
      }
    }
  /**
  *  
  *  @param width 
  *  @param height
  *  @param default char [default, w, h]
  *           default = scale with white space, 
  *           w = fill according to width, 
  *           h = fill according to height
  *  
  */
    public function resize($width = 0, $height = 0, $default = '') {
      if (!$this->info['width'] || !$this->info['height']) {
       return;
      }
      $xpos = 0;
      $ypos = 0;
      $scale = 1;
  
      $scale_w = $width / $this->info['width'];
      $scale_h = $height / $this->info['height'];
  
      if ($default == 'w') {
        $scale = $scale_w;
      } elseif ($default == 'h'){
        $scale = $scale_h;
      } else {
        $scale = min($scale_w, $scale_h);
      }
  
      if ($scale == 1 && $scale_h == $scale_w && $this->info['mime'] != 'image/png') {
        return;
      }
  
      $new_width = (int)($this->info['width'] * $scale);
      $new_height = (int)($this->info['height'] * $scale);      
      $xpos = (int)(($width - $new_width) / 2);
      $ypos = (int)(($height - $new_height) / 2);
                       
      $image_old = $this->image;
      $this->image = imagecreatetruecolor($width, $height);
        
      if (isset($this->info['mime']) && $this->info['mime'] == 'image/png') {    
        imagealphablending($this->image, false);
        imagesavealpha($this->image, true);
        $background = imagecolorallocatealpha($this->image, 255, 255, 255, 127);
        imagecolortransparent($this->image, $background);
      } else {
        $background = imagecolorallocate($this->image, 255, 255, 255);
      }
      
      imagefilledrectangle($this->image, 0, 0, $width, $height, $background);
    
      imagecopyresampled($this->image, $image_old, $xpos, $ypos, 0, 0, $new_width, $new_height, $this->info['width'], $this->info['height']);
      imagedestroy($image_old);
         
      $this->info['width']  = $width;
      $this->info['height'] = $height;
    }
    
    public function watermark($file, $position = 'bottomright') {
        $watermark = $this->create($file);
        
        $watermark_width = imagesx($watermark);
        $watermark_height = imagesy($watermark);
        
        switch($position) {
            case 'topleft':
                $watermark_pos_x = 0;
                $watermark_pos_y = 0;
                break;
            case 'topright':
                $watermark_pos_x = $this->info['width'] - $watermark_width;
                $watermark_pos_y = 0;
                break;
            case 'bottomleft':
                $watermark_pos_x = 0;
                $watermark_pos_y = $this->info['height'] - $watermark_height;
                break;
            case 'bottomright':
                $watermark_pos_x = $this->info['width'] - $watermark_width;
                $watermark_pos_y = $this->info['height'] - $watermark_height;
                break;
        }
        
        imagecopy($this->image, $watermark, $watermark_pos_x, $watermark_pos_y, 0, 0, 120, 40);
        
        imagedestroy($watermark);
    }
    
    public function crop($top_x, $top_y, $bottom_x, $bottom_y) {
        $image_old = $this->image;
        $this->image = imagecreatetruecolor($bottom_x - $top_x, $bottom_y - $top_y);
        
        imagecopy($this->image, $image_old, 0, 0, $top_x, $top_y, $this->info['width'], $this->info['height']);
        imagedestroy($image_old);
        
        $this->info['width'] = $bottom_x - $top_x;
        $this->info['height'] = $bottom_y - $top_y;
    }
    
    public function rotate($degree, $color = 'FFFFFF') {
      $rgb = $this->html2rgb($color);
      
      $this->image = imagerotate($this->image, $degree, imagecolorallocate($this->image, $rgb[0], $rgb[1], $rgb[2]));
          
      $this->info['width'] = imagesx($this->image);
      $this->info['height'] = imagesy($this->image);
    }
      
    private function filter($filter) {
      imagefilter($this->image, $filter);
    }
            
    private function text($text, $x = 0, $y = 0, $size = 5, $color = '000000') {
      $rgb = $this->html2rgb($color);
          
      imagestring($this->image, $size, $x, $y, $text, imagecolorallocate($this->image, $rgb[0], $rgb[1], $rgb[2]));
    }
    
    private function merge($file, $x = 0, $y = 0, $opacity = 100) {
        $merge = $this->create($file);
        $merge_width = imagesx($image);
        $merge_height = imagesy($image);
            
        imagecopymerge($this->image, $merge, $x, $y, 0, 0, $merge_width, $merge_height, $opacity);
    }
      
  private function html2rgb($color) {
    if ($color[0] == '#') {
      $color = substr($color, 1);
    }
    
    if (strlen($color) == 6) {
      list($r, $g, $b) = array($color[0] . $color[1], $color[2] . $color[3], $color[4] . $color[5]);   
    } elseif (strlen($color) == 3) {
      list($r, $g, $b) = array($color[0] . $color[0], $color[1] . $color[1], $color[2] . $color[2]);    
    } else {
      return false;
    }
    
    $r = hexdec($r); 
    $g = hexdec($g); 
    $b = hexdec($b);    
    
    return array($r, $g, $b);
  }  
}
?>